dt-bindings: Add vendor prefix for arcx / Archronix

arcx Inc. is an engineering company which provides advanced
embedded systems and consulting services.

Archronix is a technology design and product engineering firm
specializing in hardware control systems and enabling software.
Clients include OEM's in the transportation, aerospace,
medical and commercial sectors.

Websites:
	http://www.arcx.com/
	http://www.archronix.com/Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -36,6 +36,7 @@ aptina	Aptina Imaging
 arasan	Arasan Chip Systems
 archermind ArcherMind Technology (Nanjing) Co., Ltd.
 arctic	Arctic Sand
+arcx	arcx Inc. / Archronix Inc.
 aries	Aries Embedded GmbH
 arm	ARM Ltd.
 armadeus	ARMadeus Systems SARL